Louvered catalytic converter for purifying exhaust gases

ABSTRACT

A louver construction especially suitable for catalytic converters of the type containing catalyst particles comprises elongated openings defined by spaced lips which are formed in the walls of the catalyst bed to extend at substantially right angles to the walls and in a direction away from the catalyst material.

United States Patent [191 Balluff [11,1 3,840,346 [451 Oct. 8, 1974 1 LOUVERED CATALYTIC CONVERTER FOR PURIFYING EXHAUST GASES [75] Inventor: Robert N. Balluff, Rives Junction,

Mich.

[73] Assignee: Tenneco Inc, Racine, Wis.

[22] Filed: Apr. 11, 1972 [21] Appl. No.: 242,995

[52] US. Cl. 23/288 F, 181/57, 181/59,

[51] Int. Cl. FOln 3/14, BOlj 9/04 [58] Field of Search 23/288 P; 181/47 R, 48, 181/57, 41, 42, 59; 60/299 [56] References Cited UNITED STATES PATENTS 2,761,525 9/1956 Moss 181/47 R X 3,181,647 5/1965 Schomburg.....'. 181/57 X 3,252,767 5/1966 Lentz 23/288 F 3,263,772 8/1966 lrwin et al 181/59 3,290,121 12/1966 Malkiewicz..... 23/288 F 3,389,764 6/1968 Kelso 181/48 3,479,145 11/1969 Lentz 23/288 F 3,511,617 5/1970 Lyben 23/288 F 3,771,969 11/1973 Scheitlin .23/288 F Primary Examiner-Barry S. Richman Attorney, Agent, or Firm-Harness, Dickey & Pierce I [57] ABSTRACT A louver construction especially suitable for catalytic converters of the type containing catalyst particles comprises elongated openings defined by spaced lips which are formed in the walls of thecatalyst bed to extend at substantially right angles to the walls andin a direction away from the catalyst material.

4 Claims, 8 Drawing Figures LOUVERED CATALYTIC CONVERTER FOR PURIFYING EXHAUST GASES BRIEF SUMMARY OF THE INVENTION It is the purpose of this invention to provide an improved louver construction for use with beds of nonmetallic particulate material, such as catalyst pellets or fibrous, acoustic packing, which will minimize losses of the material due to abrasion and give other advantages.

This purpose is accomplished by forming the louvers with lips that extend outwardly of the walls of the bed to minimize the sharp edges that are presented to the particles and to minimize gas turbulence.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross-section through an illustrative form of catalyst converter having louvers embodying the invention;

FIG. 2 is a cross-section along the line 2-2 of FIG.

FIG. 3 is a partial plan view of a blank of metal prior to shaping into a tube to show the louver construction;

FIG. 4 is a partial end view of the blank of FIG. 3;

FIG. 5 is an enlarged cross-section along the line 55 of FIG. 3;

FIG. 6 is a view similar to FIG. 3 of a modification;

FIG. 7 is an enlarged section along the line 7-7 of FIG. 6; and

FIG. 8 is an enlarged section along the line 8-8 of FIG. 6.

DESCRIPTION OF THE INVENTION The catalyst converter 1 has an outer shell 3 which is preferably oval in cross-section and has an inlet header 5 closing one end and an outlet header 7 closing the other end, the headers being secured to the ends of the shell 3 in gas tight rolled joints 8. The inlet header 5 has an inlet opening 9 and located around it is a reinforcement pad 11 with threaded holes 13 whereby an inlet casting or exhaust pipe flange may be bolted to the converter to deliver exhaust gas through the opening 9. The outlet header 7 has an outlet opening 15 around which is a relatively thick reinforcement pad 17 with threaded opening 19 whereby an outlet casting or tailpipe flange may be secured to the converter 1 to carry gases away from it.

Inside of the shell 3 and in alignment with the inlet opening 9 is a perforated tube 21 which is rolled up from a blank 23 with opposite edges 24 of the blank being interlocked in a lock seam 25. A perforated shell 26 formed, like tube 21, from a rolled up sheet, surrounds the tube 21 and the space between the two comprises the catalyst bed 27 which, in actual use of the converter 1, is filled with suitable catalyst pellets. As seen in FIG. 2, the shell 26 is concentric with the tube 21 but engages the oval shaped shell 3 along the minor diameter thereof as indicated at 28 whereby the outer shell supports the inner shell 26. The tube 21 is supported at its inlet end in the pad 11 and may be spotwelded to it as indicated by the xs 31. The downstream end of the tube 21 slidably fits in-a cup-shaped recess 30 in a partition 31 that closes the downstream end of the shell 26 and also the downstream end of the tube 21. The upstream end of the shell 26 may be united to the tube 21 by means of a transverse partition 33 which acts to close the upstream end of the bed 27. A flow distributing partition 35 may be mounted inside the tube 21 and catalyst pellet flow controlling partitions 37 may be mounted inside the bed 27.

In operation, exhaust gas to be treated will enter the inlet opening 9 and flow along the length of the tube 21. It will then pass radially from the tube through the bed 27 and through the shell 26 into spaces 39 or 41 on opposite sides of the shell 23 from which it can flow to a transverse chamber 43 at the downstream end of the converter which empties the gas into the outlet opening 15 through which it can flow away from the converter. 1

In accordance with this invention, the openings 45 in the tube 21, and preferably the openings 47 in the shell 26, are formed in a special way which is best shown in FIGS. 3 to 5. As can be seen, the openings are each substantially rectangular in shape, substantially uniform in size, shape, and spacing, and are formed in rows that extend circumferentially with respect to the axis of the tube 21 or the axis of the shell 26. The holes in adjacent rows are staggered as indicated in FIGS. 1 and 3 and it is preferable that the openings in one row be longitudinally aligned with the space 49 between adjacent openings in the adjacent row as this minimizes the possibility of fracture or tearing of the metal. When the holes 45 (or 47) are formed, the. longitudinally ex tending edges are retained instead of being sheared out, one way of accomplishing this being by means of a lancing operation. They are bent in forming to extend at approximately right angles to the plane of the blank so that they appear as lips or ribs 51 and 53 on opposite sides of the opening. A smoothly contoured streamline appearance can be achieved, as indicated at 55 in FIG. 5, and it is apparent that the lips will function to direct the gas flowing through them to flow at substantially right angles to the plane of the opening.

FIGS. 6 through 8 show a slightly different form of hole l45 for a blank 23'. In this form the holes are I sheared or lanced out to have longitudinal side ribs or lips 15] and 153 to give a smoothly contoured opening as seen at 155. In this form the ends of the elongated holes are rounded and provided with lips or ribs 157 and 159 that blend into the side lips 151 and 153. A slight split or part at 161 may be formed by the laneing or shearing operation in the lips 157 and 159 but the overall appearance and shape is rounded and streamlined. The holes 145 are preferably sized, spaced, and placed in the manner described for holes 45 and function in the same manner. I

With the louver structure and arrangement described, the walls or grids (tube 21 and shell 26) are inherently strong since no material is. removed in making the openings 45, 47, and 145 and the lips or ribs improve the strength of the wall, as compared with plain openings, so that sheet thickness limitations are not as critical. The lips and contours direct flow substantially perpendicular to the wall to minimize gas turbulence and pressure losses as well as catalyst losses due to abrasion across sharp edges.

While the invention has been described and illustrated in connection with a catalyst bed, it is also of substantial value in ordinary packed, mufflers where fibrous materials of various types are packed in a space or bed around a louvered gas flow tube. In these mufflers the louvers may be formed as described herein and the lips preferably arranged to project away from the packing.

Modifications may be made without departing from the spirit and scope of the invention.

1 claim:

1. An exhaust gas treating device comprising a housing having a means providing a bed of gas treating catalyst material therein, a gas flow conduit comprising a metal tube having a longitudinal seam extending along its entire length and parallel to the axis of the tube and a plurality of rows of holes in the tube opening into said bed, each row being transverse to the seam and axis of the tube and containing a plurality of substantially identical substantially rectangular holes having their long sides extending parallel to said seam and axis and rounded ends, lips formed in the tube to define each of said long sides and said rounded ends and extending at substantially right angles to the tube and away from the bed.

2. In a catalytic converter for the treatment of exhaust gas in an internal combustion engine or the like, means providing a catalyst bed having an inlet wall and an outlet wall, the space between said walls comprising said bed, each of said walls being perforated and the perforations in at leastone of said walls being in the form of elongated substantially rectangular openings and including lips formed on opposite longitudinal sides of said openings and around the opposite ends of the openings, said lips being integral with at least one of said walls and extending at substantially right angles to at least one of said walls in a direction away fromsaid bed.

3. A converter as set forth in claim 2 wherein said formed in said other wall and in said rows. 

1. AN EXHAUST GAS TREATING DEVICE COMPRISING A HOUSING HAVING A MEANS PROVIDING A BED GAS TREATING CATSLYST MATERIAL THEREIN, A GAS FLOW CONDUIT COMPRISING A METAL TUBE HAVING A LONGITUINAL SEAM EXTENDING ALONG ITS ENTIRE LENGTH AND PARALLEL TO THE AXIS OF THE TUBE AND A PLURALITY OF ROWS OF HOLES IN THE TUBE OPENING AT SAID BED, EACH ROW BEING TRANSVERSE TO THE SEAM AND AXIS OF THE TUBE AND CONTAINING A PLURALITY OF SUBSTANTIALLY INDENTICAL SUBSTANTIALLY REGULAGULAR HOLES HAVING THEIR LONG SIDES EXTENDING PARALLEL TO SAID SEAM AND AXIS AND TOUNDED ENDS, LIPS FORMED IN THE TUBE TO DEFINE EACH OF SAID LONG SIDES AND SAID ROUNDED ENDS AND EXTENDING AT SUBSTANTIALLY RIGHT ANGLES TO THE TUBE AND AWAY FROM THE BED.
 2. In a catalytic converter for the treatment of exhaust gas in an internal combustion engine or the like, means providing a catalyst bed having an inlet wall and an outlet wall, the space between said walls comprising said bed, each of said walls being perforated and the perforations in at least one of said walls being in the form of elongated substantially rectangular openings and including lips formed on opposite longitudinal sides of said openings and around the opposite ends of the openings, said lips being integral with at least one of said walls and extending at substantially right angles to at least one of said walls in a direction away from said bed.
 3. A converter as set forth in claim 2 wherein said end lips and the ends of the openings are rounded.
 4. A converter as set forth in claim 2 wherein said openings are formed in rows, the openings in adjacent rows being staggered and spaced so that openings in one row are transversely aligned with spaces between openings in an adjacent row, said one wall being tubular and having a longitudinal axis, said rows extending transversely to said axis, the other of said walls also being tubular and said openings and lips also being formed in said other wall and in said rows. 